Project Summary Background: Undifferentiated complaints such as abdominal pain present a diagnostic challenge to primary care physicians, in part because clear evidence or guidelines describing best diagnostic practices are lacking. We have the opportunity to study the way undifferentiated complaints are assessed using electronic health record (EHR) data. Overall goal: To develop and apply a new methodology, which uses EHR data to study diagnostic pathways (the steps taken for diagnostic evaluation) for undifferentiated complaints. We will use undifferentiated abdominal pain in an adult primary care population as the test case. Relevance to AHRQ's Area of Interest: The proposed research will result in a new health IT methodology for identifying diagnostic pathways using EHR data. This methodology will provide the groundwork needed to use integrated data and health IT knowledge management in order to improve diagnostic decision making. Specific Aims and Methods: (1): To identify diagnostic pathways for undifferentiated abdominal pain including diagnostic testing, procedures, prescriptions, referral and follow-up; (2) Through semi-structured interviews, to identify reasons for specific diagnostic practices among physicians. Long-term Objective: The eventual goal of the proposed research will be to apply our EDW methodology to study outcomes associated with different diagnostic pathways, thereby identifying best diagnostic practices for undifferentiated abdominal pain and eventually a variety of other undifferentiated complaints.